Lifting column provided with linear transducer

Abstract

A lifting column provided with a powered lifting mechanism ( 3, 4, 5 ) which moves a loading bucket ( 7 ) along the vertical axis of the column. The column comprises a linear transducer ( 20, 30 ) which directly measures the height reached by the loading bucket and continuously transmits the read values to a computer unit ( 33 ). The invention further relates to an apparatus comprising a plurality of such columns and a central unit which compares the height of the various bucket and control the power group of the columns in order to maintain the various heights at the same level.

1 . Lifting column comprising a vertical shoulder ( 1 ) and a lifting thrust ( 7 ) displaced along said shoulder by an upper power group ( 3 ), characterized in that it comprises a linear transducer able to read and to transmit to a microprocessor unit the height values of said thrust.  
     
     
         2 . Lifting column according of    claim 1   , wherein said transducer consists of a fixed part integral to the shoulder and a movable part integral to said thrust.  
     
     
         3 . Lifting column according of    claim 2   , wherein said fixed part is a vertical linear meter applied to said shoulder; and said movable part comprises at least one linear reader ( 20 ) applied to a first body integral to said thrust and directly coupled with said meter; a microprocessor unit ( 33 ) receiving the data read by the reader ( 20 ) and able to process these data in order to extract therefrom the displacement value of the thrust.  
     
     
         4 . Lifting column according to    claim 3    wherein said thrust ( 7 ) is supported by a first nut ( 5 ) vertically displaced by a spindle ( 4 ) operated by group ( 3 ) and housed inside said shoulder.  
     
     
         5 . Lifting column according to    claim 4   , wherein nut ( 5 ) presents an upper spherical surface ( 51 ) supporting a corresponding lower surface of a support ring ( 6 ) mounted in a corresponding seat ( 61 ) of the thrust ( 7 ).  
     
     
         6 . Lifting column according to    claim 3   , wherein it comprises a second reader ( 30 ) fixed to a second movable body ( 8 ) and coupled with said meter at a prefixed distance (A) from said first reader ( 20 ).  
     
     
         7 . Lifting column according to    claim 6   , wherein said second movable body is a safety nut ( 8 ) vertically displaced by said spindle ( 2 ).  
     
     
         8 . Lifting column according to    claim 7    wherein said safety nut ( 8 ) is engaged with the spindle ( 4 ) at a prefixed distance (B) from the first nut ( 5 ).  
     
     
         9 . Lifting column according to    claim 6    wherein at least one of said optical readers ( 20 ,  30 ) performs a continuous reading of the binary meter and sends the read data to the unit ( 33 ).  
     
     
         10 . Lifting column according to    claim 8    wherein the case ( 32 ) of the reader ( 30 ) houses the microprocessor unit ( 33 ) connected with both the readers and controlling the reading operations and the processing of the read data.  
     
     
         11 . Lifting column according to    claim 9   , wherein said microprocessor unit continuously processes the data received from the optical readers ( 20 , 30 ) and compares the displacement values of thrust ( 7 ) and nut ( 8 ).  
     
     
         12 . Lifting column according to    claim 1   , wherein said linear meter is a binary optical meter and said readers ( 20 ,  30 ) are optical readers.  
     
     
         13 . Lifting column according to    claim 11   , wherein said binary meter is printed on a vertical tape ( 9 ) applied to said shoulder ( 1 ).  
     
     
         14 . Lifting column according to    claim 11   , wherein said binary meter is printed on a vertical tape ( 9 ) applied to said shoulder ( 1 ).  
     
     
         15 . Lifting column according to    claim 6   , wherein said readers consist of an array of optical sensors.  
     
     
         16 . Lifting column according to    claim 1   , wherein said thrust ( 7 ) can vertically slide along the shoulder ( 1 ) being guided by four rolls ( 11 ,  12 ) rotating on vertical walls of the shoulder.  
     
     
         17 . Lifting column according to    claim 1   , wherein shoulder ( 1 ) is supported by a base element ( 2 ) provided with a trolley ( 40 ) by which it is possible to displace the column.  
     
     
         18 . Lifting column according to    claim 1   , wherein said microprocessor unit continuously processes the height values received from said transducer.  
     
     
         19 . Lifter apparatus comprising a plurality of lifting columns ( 10 ) according to at least one of claims  1 - 18  and provided with a central microprocessor unit able to receive from each unit ( 33 ) the processed data referring to the height values received from said transducer and to control the power group ( 3 ) of each column ( 10 ) in order to guarantee the static stability of the lifted load.